The hydraulic shock absorbers are extensively used in the automotive industry and intended to work under even relatively high hydraulic pressures and in a highly contaminated environment (water, dust, mud). The seal for the pressurized oil contained in the shock absorber must be consequently protected by a sealing assembly known as “dust seal”, arranged between the rod and the mouth of the shock absorber body, in order to preserve its function over time.
This sealing assembly is subject in application, as a consequence of its position, to maximum radial deformations, in particular when a temporary offset positioning occurs between the shock absorber rod or the suspension fork and the body of the shock absorber or of the suspension, e.g. caused by a high excursion of the rod or fork accompanied by the application of side loads, which determine an oblique positioning of the rod or fork with respect to the symmetry axis of the sealing lip which acts thereon, usually loaded by a radial spring.
A similar problem may occur also in other situations, e.g. in static seals arranged between motor head and injectors, in the case in which seal seat and injector seat are not perfectly aligned.
Italian patent application TO20100689 solves the problem by means of a sealing assembly consisting in an annular sealing element made of elastomeric material provided with a sealing lip and a reinforcement ring at least partially embedded in the sealing element, to which a guide bush made of relatively rigid material, e.g. a polymer, intended to couple in application with the rod of the shock absorber or the suspension fork, is snap-fitted.
Although satisfactory, the sealing assembly described above requires the use of several components and may display insufficient performance in presence of relatively high offset positions. U.S. Pat. No. 5,855,375 does not solve any of these problems.
It is the object of the present invention to provide a sealing assembly which is free from the described drawbacks, and which has small dimensions, low cost and short production times and which at the same time has good sealing performance with regards to external contaminants also in presence of high offset positions of the mechanical elements between which it is inserted in application, which could damage the contact between sealing lip and member with which it cooperates, despite the presence of a radial compression spring of the sealing lip.